If your credit rating is bad, you can take steps to improve it. This is a bureaucratic chore, but can save you hundreds, if not thousands of pounds.
Getting a mortgage is so stressful, and getting a house so desirable, that people want to get it over with quickly. So they sign up to bad deals. Then their marriage breaks down two years later. The drip-drip effect having no money at the end of the month is quietly corrosive.

Improve your credit-rating. Find out what it is at Equifax, Experian, TransUnion and/or CallCredit. Lenders may access them all. Then do the following:
- Make sure you are on the electoral register.
- Satisfy liens and public judgements, such as in the County Court (CCJs).

- Correct errors, including erasing judgements older than seven years. Paid-off debts can be legitimately recorded up to seven years after settlement.
- Close unneeded accounts. Close them off slowly , not all at once. Keep only two credit cards. These should include your oldest card, as that has the longest credit history associated with it.
- Pay off credit cards. Keep balances low, and paid off on time.
- Open a savings account at your bank.
- Keep your debt low; below 75% of available credit.

- Build a good payment history. Pay your bills on time!
Then do something unusual; go for a walk in a green area and think over whether you need a mortgage at all.
If you do, what do you want it to do for you?
What you could do to get the property you want, without signing over half your income for the next thirty years?
Some options are:
Self-build: Are you up for the challenge of building your own home? If you have a site, you can put a 'kit house' on it. This is one whose design has been tried and tested, and which can be put up quickly. There are innovations coming out in house building all the time; consider taking advantage of them, and saving some money.
Buying and letting: Buy a place, do the minimum to tart it up, and rent out a room. You need to watch out for taxation of the rental income, but it could get you a bigger place, or a smaller place paid-off faster.
Buy At Auction: This is a popular idea, but problematical in practice. You have to factor in the auctioneer's fees, and the phenomenon of 'auction fever'; some newbies get very excited at an auction. They bid way over the value of the property.

Also, hardened auction-goers buy houses the way you or I buy a pair of shoes. They buy 'em, tart 'em up, then flip them on, often for quite a small profit. This makes for tough competition.
It's best to get pally with an estate agent, and take your time. These guys get wind of the best deals, and notify their friends first. You might get lucky, and get a great house, at a good price, from someone who has to sell in a hurry.